Olaparib for the treatment of breast cancer

INTRODUCTION

Mutations in BRCA1 and BRCA2 genes account for around 2-3% of breast cancer events and more than 10% of triple negative breast cancers. Olaparib (Lynparza®), an orally administered PARP inhibitor, demonstrated clinical benefit in a phase III trial for mutated BRCA-positive HER2 negative metastatic breast cancer. Areas covered: This review gives an overview of available preclinical and clinical data regarding olaparib, including its chemistry, mechanism of action, pharmacokinetics and pharmacodynamics, and evidence supporting antitumor efficacy and safety profile in breast cancer patients. Expert commentary: Olaparib improves progression-free survival in germline BRCA mutated HER2 negative metastatic breast cancer patients as compared to standard chemotherapy, with a manageable toxicity profile. Efficacy is of clinical relevance especially in the context of triple negative breast cancer. However, several aspects, such as sequencing or combination of these agents with other anticancer agents and identification of appropriate biomarkers, still need to be clearly defined.

Olaparib for the treatment of epithelial ovarian cancer

INTRODUCTION

Despite recent advances in the management of epithelial ovarian cancer, overall survival rates remain poor, and there is a pressing need to develop novel therapeutic agents and maintenance strategies to improve outcomes for women with this disease. Olaparib, a potent oral poly(ADP-ribose) polymerase (PARP) inhibitor, has demonstrated antitumor activity in women with ovarian cancer, associated with homologous recombination deficiency.

AREAS COVERED

This review outlines the rationale for PARP inhibitor therapy in ovarian cancer and summarizes the efficacy and tolerability data for olaparib to date. Ongoing phase III clinical trials of olaparib in ovarian cancer will be discussed.

EXPERT OPINION

There are a number of issues regarding the optimal use of olaparib in ovarian cancer, including the identification of a homologous recombination deficiency signature to predict treatment response, establishment of the optimal treatment setting (maintenance or relapsed disease), and evaluation of cost-effectiveness. Finally, the long term consequences of PARP inhibitors, including the risk of myelodysplasia and acute myeloid leukemia need to be quantified in ongoing large phase III clinical trials.